This invention relates to a desktop viewer for transparent images, and more particularly to an improvement of a desktop film viewer to facilitate viewing of positive or negative transparencies for checking and finding desired ones from a large number of transparencies.
A typical desktop film viewer for transparent images of the prior art comprises a housing in the form of a rectangular parallelepiped having a light source such as fluorescent lamp housed therein and closed at a top by a transmission diffusion plate which transmits light but simultaneously diffuses the light.
This viewer exhibits its effective function when the transparencies are arranged on a horizontal diffusion plate for viewing them. However, a user of the viewer cannot effectively view the transparencies without removing files bound as a binder containing the transparencies or in an inclined condition of the transparencies at a particular angle facilitating the user's viewing. This difficulty results from edge walls having at least 5-6 cm height surrounding the circumference of the viewer. Accordingly, the user cannot select his viewing manner at will.
The inventor has proposed a desktop film viewer which was patented as U.S. Pat. No. 4,468,873. The proposed desktop film viewer comprises a wedge-shaped housing having a bottom wall, an inclined top with a diffusion plate and sidewalls enclosing a space between the bottom wall and the top, so that the housing can be inserted between file sheets of a binder bound like an album. A light source is located at a center of a rectangular portion connecting the highest ends of the sidewalls and a main reflector an inside of a bottom of the housing. Sub-reflectors are located on insides of the tapered or triangular sidewalls and auxiliary reflectors are arranged above and below the light source. These reflectors forms a composite reflector. By tilting the auxiliary reflectors at suitable angles, the transmission diffusion plate is uniformly illuminated by the light source with the aid of the composite reflector. Accordingly, after the housing has been inserted between file sheets, a user can view the transparencies clearly irrespectively of the relatively shallow housing.
With such a desktop film viewer, the user can view the transparencies properly under the condition of the binder opened on right and left sides as illustrated in FIG. 1a. However, in case of the binder opened forward and rearward as illustrated in FIG. 1b, a target page is located remote from eyes of the user, so that the user must pivotally raise the target page until it assumes a position near to the user sufficient to facilitate the viewing of the user. Accordingly, the operation of the viewer having the comparatively shallow housing is troublesome.